Access sheaths, such as ureteral access sheaths, may be used to gain access to body cavities and lumens during endoscopic and laparoscopic surgery, and by other procedures that generally use minimally invasive techniques. Thus, a ureteral access sheath may be used with an endoscope for finding and removing kidney stones, and may also be used in other applications, such as for access to bile ducts. Other applications for which an access sheath has been used include vascular procedures, as well as procedures requiring gastro-intestinal access, uterine access, and bronchial access. Thus, sheaths may be used in combination with endoscopes, hysteroscopes, sigmoidoscopes, bronchoscopes, and many other types of instruments meant for minimally-invasive techniques.
Using a sheath provides for a way to protect the tissues of a patient during a procedure. For instance, if a kidney stone is to be removed, a retrieval basket may require many passages back and forth across a patient's ureter to remove stone fragments. A wire basket or other device is first passed through the ureter to retrieve stone fragments, and then passes back through to remove the captured fragments. Passing the basket through an access sheath instead of the ureter itself avoids trauma to the ureter and surrounding tissues.
One problem that is common to all procedures in which these devices are used is that more and more is expected from the surgeon and operating team. For instance, now that an access sheath may be used for access across a ureter, the surgeon may wish to use the sheath for access not only for an endoscope, but also for multiple endoscopic instruments, such as a retrieval basket, a stone “blocker” or backstop, a fiberoptic laser to break up stones, a safety wire, an operating wire, or a system to provide irrigation or to instill contrast agents. While all these systems are desirable, it is difficult to operate them all at the same time and through the same access sheath. Thus, the surgeon may instead use an endoscope.
Removal of kidney stones and other calculi within body cavities may be accomplished with an endoscope or other expensive piece of equipment. An endoscope is inserted into the patient, desirably using a body passageway, such as a urethra, a ureter, or a blood vessel. The endoscope includes an optical system, a working channel, and a way to maneuver the endoscope so that the surgeon can accomplish a therapeutic or diagnostic procedure. The surgeon positions the endoscope so that the surgeon can observe the desired body part of the patient using the optical system, with irrigation if necessary. The surgeon then uses at least one instrument, such as a laser fiber or a grasper, to break up and remove objects from the body passageway. The endoscope may also be used for diagnostic purposes, such as for observing the desired portion of the patient and then taking a biopsy sample.
Flexible endoscopes are very expensive pieces of equipment. When this application refers to endoscopes, primarily flexible endoscopes are intended. They may cost from $10,000 to $20,00, and are typically used for no more than 10-15 procedures before they require a $3000-$5000 overhaul. Part of the problem may be the very extensive cleaning and sterilization that is required after each patient. After the overhaul, the endoscope may typically be serviceable for only another 10 procedures before requiring additional overhaul. Thus, endoscopes are very expensive and they require great attention and maintenance. Because damage is not always apparent to hospital personnel, the need for repair or an overhaul may become obvious during a medical procedure, causing a delay in completing the procedure. In addition, multiple endoscopes must be kept in stock to assure their availability at all times.
What is needed is a better way to access body cavities during endoscopic and laparoscopic surgery. Highly desirable would be an access sheath with greater capabilities, the sheath adaptable for use in a variety of procedures, while still allowing important access functions. What is needed is an access sheath that allows the surgeon to best use valuable space in the sheath or other minimally-invasive device used on the patient. What is needed is a way to better use the space available to a surgeon with an access sheath.